Clutch control system for automatic machines and the like



April 13, 1965 G. MYSKA 3,178,000

CLUTCH CONTROL SYSTEM FOR AUTOMATIC MACHINES AND THE LIKE Filed Sept. 13, 1962 3 Sheets-Sheet 1 INVENTOR' Fl 6 1 GUNTER MYSKA AGENT April 13, 1965 G. MYSKA 3,178,000

CLUTCH CONTROL SYSTEM FOR AUTOMATIC MACHINES AND THE LIKE Filed Sept. 13, 1962 3 Sheets-Sheet 2 37 FIGQ 93 81 l H! l I IIHI 33 so 49 45 44 43 F IG. 3

GUNTER MY SKA INVENTOR.

G. MYSKA 3,178,000 CLUTCH CONTROL SYSTEM FOR AUTOMATIC MACHINES AND THE L IKE April 13, 1965 3 Sheets-Sheet 3 Filed Sept. 13, 1962 FIG.5

FIGA

FIGB

GUNTER MYSKA INVENTOR.

ibis BY m g.

AGENT 3,173,0tlil CLUTCH QQNTRfiL SYSTEM F931 AUTQMATHQ MACHENESS AND THE LIKE Giinter Myslra, Bielefeld, Germany, assignor to Dnrlropp- Wei-kc Alttiengesellschaft, Bielefeld, Germany, a corporation of Germany Filed Sept. 13, 1962, Ser. No. 223,466 6 Claims. ((Il. 192-125) My present invention relates to a system for controlling the operation of machines operating on'sheet material, such as sewing machines, which are successively to perform the identical operations (e.g., the sewing of buttons or buttonholes) at spaced locations along a piece of such material.

In my prior Patent No. 2,906,217, issued September 29, 1959, I have disclosed a control system of this type wherein a program unit determines the correct spacing of successive working positions along the sheet by the generation of counting pulses during relative displacement of the machine and the sheet; when the number of pulses has reached a predetermined count, the displacement drive is deactivated until the necessary operation (e.g., the stitching of a button or buttonhole) has been completed at the location so selected.

The general object of my present invention is to provide means in such system for accurately and automatically determining the location of the first working position in relation to a transverse edge of the sheet to be worked on, the remaining positions being thereupon established in the general manner described in my aforementioned patent.

A more particular object of this invention is to provide an improved program unit having means for selectively establishing the locations of each working position in terms of its distance from the sheet edge used as a reference.

A further object of my present invention is to provide means in such system for simultaneously controlling the operation of a plurality of machines whose respective working positions and/or reference edges may be oifset from one another while the relative spacing of successive working positions is the same for all of these machines.

In accordance with the instant invention I provide, in combination with mechanism for relatively displacing a piece of sheet material on one or more machines (e.g., sewing machines of the group-stitching type) adapted to operate thereon, a scanning device rigidly but preferably adjustably positioned with respect to such machine or machines for ascertaining the passage of a sheet edge through a reference position; this reference position is advantageously located in the immediate vicinity of the operating tool or tools (e.g., sewing needle) of the machine. A distance-measuring device, such as a countingpulse generator, is actuated by the scanning device upon the detection of the proximal transverse sheet edge to measure the further relative displacement of sheet and machine and to halt this displacement as soon as the eX- tent thereof has reached a numerical value stored in a program unit. The machine then performs its work, as in the system of my prior patent, and between operations advances to other positions relative to the sheet under the control of the same'program unit and measuring device. In a preferred embodiment the counting-pulse generator serving as the distance-measuring device, which is me chanically driven by the relative displacement between machine carrier and sheet support to produce a train of photoelectric pulses at the rate of such displacement, has its power supply cut off by the scanning device prior to detection of the sheet edge so that no pulses appear in its output even though its coupling with the driving mechanism remains unaltered.

United States Patent 3,17%,dh0 Fatented Apr. 13, 19%5 If two or more machines are to be simultaneously controlled by such a system, each machine is advantageously equipped with its own scanning device. These devices are so coupled with the counting-pulse generator or equivalent distance-measuring means as to actuate the latter only after each scanning device has detected its respective reference edge; prior thereto, i.e., with at least one machine still searching for its edge, the remaining machines are halted at their respective edges so that all will then advance simultaneously for the same relative starting position. Any relative staggering of the working positions of the several machines is provided for by a corresponding offsetting of the individual scanners from their respective working tools; such a situation will occur, for example, if a set of buttons have to be sewn onto a garment (e.g., a shirt) along one longitudinal edge while concurrently a set of mating longitudinal buttonholes must be finished along a parallel longitudinal edge, the staggering arising from the fact that each buttonhole starts at a location which is disaligned with the center of the corresponding button.

The program unit I prefer to utilize in a system of this character comprises, pursuant to a further feature of my invention, a cam carrier such as a rotatable disk divided into a plurality of sectors,the pattern of cams in the first sector determining the distance of the first working position from the reference edge whereas the cams in the remaining sectors establish the spacing between successive Working positions. For this purpose the disk may be provided in each sector with a multiplicity of perforations into which respective pegs serving as camming elements can be selectively inserted according to a desired pattern; the numerical value stored in each sector may thus be readily changed through a rearrangement of the pegs.

The above and other objects, features and advantages of my present invention will become more fully apparent from the following detailed description of a preferred embodiment, reference being made to the accompanying drawing in which:

FIG. 1 is a somewhat diagrammatic overall view of a system according to the invention, serving a pair of concurrently operable sewing machines;

FIG. 2 is a plan view of a program disk forming part of this system;

FIG. 3 is a cross-sectional view taken on the line III III of FIG. 2;

FIG. 4 is a top the system;

FIG. 5 is a partial plan view of a piece of sheet material to be worked upon by the sewing machines; and

FIG. 6 schematically illustrates the relative initial displacement of the two sewing machines and the workpiece shown in FIG. 5.

'In FIG. 1 I have shown a common drive motor 201 for a pair of sewing machines, designated ltltla and will), whose bases 22a, 22b ride by means of wheels 23a, 23b on parallel rails 24a, 24b. Machines liltla and Hill!) are a buttonhole-stitching machine and a button-sewing machine, respectively. The rails 24a, 24b extend on opposite sides of a supponting table 28 for a workpiece 29, such as a sheet of fabric, whose edge E extends generally transversely to the rails. The exact position of this edge is not critical, yet the longitudinal sheet edges Ea and Eb ought to be maintained parallel to the rails by suitable sheetelamping means not further illustrated. It will be asssumed that the machines a and ltltlb are to stitch a series of buttonholes H H etc. alongside edge Ea. and to sew corresponding buttons 13,, B etc. onto the sheet alongside edge Eb respectively.

The motor 201 carries a worm 19 which drives a worm gear 20 on a shaft 21 this shaft being coupled via a pair of electromagnetic clutches idea, 106]) with two extenview of one of the scanning devices of a photoelectric cell 205. The sprockets 104a and limb are engaged by respective chains 10 2a, 10% whose opposite ends pass around other, nondri-ven sprockets (not shown) and which are secured to the bases 22a and 221),

respectively, in order to advance the sewing machines 100a and 10% along their tracks when the motor 201 is operated and the corresponding clutches 1106a, 10% are de-energized.

An electric counter 206 is connected to be stepped by the pulse generator 203, 204, 205 via a cable 120 extending to the output or photocell 205. Counter 2% is shown to comprise three decadic counting tubes 30, 31, 32 which may be constructed and interconnected in the manner described and shown in my aforementioned Patent No. 2,906,217 ('FIG. 2). A three-stage preselector 207 enables the p-resetting of each tube to a selected numerical value from to 9 under the control of a program unit generally designated 208. The program unit comprises a perforated disk 36 which is positively keyed to a platter 35 ('FIG. 2) on the shaft 33 of a motor'34 whose operating circle includes an electromagnetic switch 209.

The sewing machines 100a, 1001) carry respective scanning devices which include a light source llrZa or 12b and a photocell 13a or 1312 juxtaposed therewith. As particularly illustrated in FIG. 4 for the scanner 12b, 13b of machine 10%, the light source and the photocell have their optical axes converging on the work-supporting surface of the machine at a location Re which in the case of machine 10011 is spaced by a distance x from the path of reciprocation of its needle 76b, for reasons that will appear hereinafter, but which in the case of machine 100a coincides with the path of needle 76a. The scanners 12a, 13a and 12b, 1% respectively control a pair of electronic relays Ma, 14b which, via a stepping switch 210 and a reversing switch 211, determine the operation of drive motor 201. The system also includes a start relay 15, a delayed-action tilting relay 16 and a main on-ofi? switch 17.

Reference will now be made to FIGS. 2 and? for a more detailed description of the program disk 36 and its associated elements. The disk is peripherally subdivided into five sectors designated S S S S and S It is formed within each of these sectors with a multiplicity -of perforations 93 which are distributed over five imaginary concentric circles s7, 38, 39, 40 and 41. The perforations 93 form seats for camming pegs 42' which are selectively inserted therein taco-operate with micro-sensit-ive switches do, d4, 45, 4-9 and 60 respectively aligned with the circles 37-4 ll, these switches lying substantially on a common radius in the region of the section line IIL IH of FIG. 2. The pegs 4-2 on circles 37, 38 and 39 actuate, via switches 43, 44 and 45, the hundredth-s, tenths and units stages A, B and C' of preselector 207 respectively associated with counting tubes 32, 3-1 and 30. Only a single peg 4 2 42 42 42 and 4-2 is disposed on circle 40 within each of sectorsVS -S to actuate the switch 209 at the endof each preselecting operation. A

further peg 4 2 lies on the circle 41 near the end of sector S but just ahead of peg 42 the function of peg 42,; being to operate the tilting relay in.

The .preselector 207 comprises three stepping switches generally designated 46, 47 and 08. Each of these stepping switches has ten bank contacts, designated from 0 to 9, which are connected to respectivepotentiometer taps in the biasing circuit of the associated counting tube (of, voltage divider-s 93, 95 and 96 in FIG. 2 of my Patent No. 2,906,217) and are swept by a respective wiper arm 90', 91 and 9 2. Wiper arm 90 of hundredths stage A is controlled, in a manner well known per se and illustrated only schematically, by a stepping magnet 87 and a restoring'magnet 90; wiper arms 91' and 92 of tenths stage B and units stage C are similarly controlled by stepping magnets 33, 89 and restoring magnets 9d, 92. Counter 2% is provided with a normally open pair of contacts 58 (corresponding to contacts at of my prior patent) which close whenever the number represented by the digital pulse trains fed into tubes 30, 3d and 32 complements to 1000 the numerical value indicated by the setting of wipers 91 and 92'.

The switch 209 comprises an electromagnet 56 with an armature 5? which can be latched in attracted position, against the force of a restoring spring 57, by a dog 55 which in turn is retractable, against the action of its own biasing spring 52, by an electromagnet 50 connected to switch d9. Armature S3 is linked with a pair of contact arms 54, 55 for the control of counter 20s and programming motor 34, respectively.

The tilting relay 16 comprises a vessel 62 containing a pool of mercury which in its illustrated normal position bridges a pair of contacts 62" and in its alternate position, into which it can be swung upon the energization of a solenoid 6d, bridges another contact pair at; coupled mechanically with vessel 62 is another mercury cont ainer 65 which upon reversal momentarily completes a circuit through a pair of contacts 65'.

A pair of bus bars 121 and 122 are energized, in the on position of switch 117, from a main source of direct current shown diagrammatically as a battery 123. An auxiliary 'D.-C. source 124 is provided for the photoelectric scanners l2al3a, lib-13b and 204-205.. A source 125 of alternating current operates the electronic relays 14a and 1412 whereas a three-phase power supply 129 is used to energize the reversible alternating-current motor 201. Reversing switch Zlli, inserted in the connection between motor 201 and its power supply, comcores, terminates in a shoe 116' which in its rightmost position, upon energization of the reverse solenoid 66, is latched by two spring-loaded detent pawls 67a, 67b respectively aligned with camming lugs 69a, 6% on machine bases 22a and 22b. A suitable restoring spring, not shown, returns the link 116 with its contact arms to its illustrated central position whenever the detents 67a, 67b are released by the lugs 69a, 6% upon the reversion of both machines a and 10% to their starting points. The forward solenoid '70 is connected to a wiper arm 71 of stepping switch 210 whose bank contacts are alternately left unconnected and connected to bus bar 122. Arm '71 can be independently advanced by'either of two stepping magnets 72, 73 acting upon a ratchet 74 through the intermediary of two pawls 94, 98 against the force of restoring springs 94' and 98'.

The machines 10%, 10011 are further provided with starting solenoids 96a, 9617 which, at the beginning of a sewing operation, actuate respective levers for clamping the fabric onto the work support of each machine. The fabric-clamping lover of machine 100a, shown at 63, also opens a circuitbreaker 64 which controls the stepping magnet 73. Stepping magnet '72 is energizable, in a manner more fully described hereinafter, under the control of counter contacts 58 or of a starting switch 81 having 7 reference edge E whereas machine 10012 is separated from its edge E by a somewhat smaller distance Db Moreover, as illustrated in FIG. 5, the first operating position of button-sewing machine 1426b occurs upon the arrival of needle 761; at an imaginary line Ob bisecting the first button B whereas the needle 76a of machine lhila must go into action upon its arrival at a line On which marks the beginning of the first buttonhole H Since the centers of button and buttonhole register with each other, line On is offset from line Ob by a distance x equally half the length of the buttonhole. Thus, the spacing of line Cu from edge E has been desi nated Da whereas the spacing of line Ob from edge E" corresponds to Db =Da +x. in order to enable both machines to advance by the same distance Da beyond their reference edges, the operating point Re of the scanner 12b, 13b of machine has been offset by the same distance x from the needle path, as previously noted with reference to FIG. 4, whereby the needle 7611 will be at Ob while the point Re is in line with 0a; at the same time the needle 7611, which does not lead the operating point of its scanner 12a, 13a, correctly stands on the same line 0a. FIG. 4 also illustrates how the spacing of x may be varied by virtue of the adjustable mounting of light source 12b with the aid of a clamping screw 110' entering a slot lid; a similar clamping screw 116" pivotally interconnects the elements 12b and 13b for a vertical adjustment of the point of intersection Re of their respective axes in accordance with the thickness of the fabric to be Worked on. Similar adjustability may, of course, also be provided for the scanning elements 12a, 13a of machine 1649a.

The on-oif switch 17, which can be rotated only clockwise as indicated by the arrow in FIG. 1, has been placed in its on position in which it bridges two terminals 126, 126' to energize the bus bar 121. Lamps 12a and 1212 are energized from D.-C. source 124, as is lamp 294 by virtue of the fact that solenoid 77a is unoperated in the nonconductive condition of cold-cathode tube 79a. Wiper arm 71a stands on one of its unmarked bank contacts so that solenoid 70 is de-energized, its companion solenoid 66 being likewise inactive since its circuit is open at contacts 65' with link 116 in its neutral position; motor Zdi is therefore at standstill.

In order to initiate a cycle of operations for the stitching of five buttonholes H H etc. and the sewing of five buttons B B etc., the operator momentarily depresses the armature 82 of starting switch 81 which is ganged with two further armatures 83a and 83b. The displacement of these latter armatures connects A.-C. source 125 across tubes 7% and 79b to ionize them inasmuch as their input circuits, which respectively include the photocells 13:: and 1312, are closed on account of the illumination of these photocells by reflected light from lamps 12a and 12b. Solenoids 77a and 77b, operating in series with these tubes, attract their armatures to maintain the ionization of the tubes independently of switch 81. Armature 82, in disengaging a contact 82/, guards against untimely operation of relay 15 and, in engaging another contact $2, energizes the stepping magnet '72 so that wiper arm 71 advances upon its next bank contact which is connected to bus bar 122. Solenoid 76 now operates and completes the forward circuit for drive motor 261 via armatures 68 and 63'. 7

With solenoid armatures 78a. and 78b lifted off their contacts, magnetic clutches 166a and 10611 are de-energized and the driving torque of the motor 201 is transmitted to sprockets 104a, itldb so that the machines 160a and with advance along rails 24a, 24b toward the edge E of fabric 29. This advance is not measured since the operation of solenoid 77a. has broken the circuit of lamp so that no counting pulses are transmitted to counter Q.

Magnet 56 operates in parallel with magnet 72, through the closed contacts 62 of tilting relay 16, to attract its armature 53 and to operate, via contact arm 55, the motor 34 of the program disk 36, this motor being subsequently held operated through the latching of armature 53 by dog 55. At the same time, the restoring magnets 9h, 91 and 92 of preselector switches 46, 47 and 48 also receive a current pulse to reset the wipers 9h, 91 and 92 to zero if they had previously been off normal. Finally, the displacement of contact arm 54 together with arm 55 restores the beams of counting tubes 30, 31 and 32 to their No. 9 positions, thus erasing any previous count.

Program disk 36, which up to this moment has been in its starting position wherein switches 43, 44, d5, 49 and 6% were aligned with the sector boundary P rotates clockwise (as viewed in FIG. 2) to step the switches 43, 44 and in the rhythm of the pegs 42 inserted into the perforations 93 on the three outer circles 37, 38 and 39 within sector S Let it be assumed that the distance Da to he traveled by the two machines 100a and 100b beyond edge E equals 54 units of length (e.g., millimeters), that the center spacing Da of the second buttonhole H from the first buttonhole H (and the identical center spacing D52 of button B B see FIG. 5) equals units, and that the spacings of subsequent buttons and buttonholes amount to 85, 85 and 91 units, respectively. The pegs 42. in sector S thus represent the complementary value of the first spacing Da i.e., 946, whereas the pegs in the remaining sectors S -S represent corresponding complements 915, 915, 915, and 909," respectively. Since the switches 43, 44 and 45 lie in series with stepping magnets 37, S3 and 89, respectively, the wiper arms 9%, 91 and 92 of preselector 207 have been advanced onto their No. 9, No. 4 and No. 6 contacts, respectively, by the time disk 36 arrives in its position P Just before the disk reaches the latter position, peg 42 operates the switch 49 to energize the magnet 50 and to unlatch the armature 53 of switch 269, thereby arresting the progam unit 268.

While the disk 36 may be driven from motor 34 through a suitable reduction gearing not further illustrated, its speed will be such that the above-described operations will have been completed before scanners 12a, 13a and i212, 1312 of the machines 106a, recs approach their respective reference edges E and E". It will be assumed, as illustrated diagrammatically in FIG. 6, that machine 16012 reaches the edge of the workpiece before machine itlil a since it has to travel only over the shorter distance Db When the beam of lamp 12b is intercepted by the fabric edge E", photocell 13b becomes nonconductive and cuts off the associated tube 7%, thereby releasing the solenoid 77b and completing a circuit for the energization of the magnetic clutch 3106b by way of solenoid armature 78b in series with armature 78a of the still energized solenoid 77a. Clutch 1661) now decouples the sprocket liidb from shaft 21 so that machine limb is arrested in a possition in which its needle 76 is spaced inwardly from edge E" by the distance x. Machine 166a continues to advance and, as the beam of its lamp 12a is intercepted by edge E, deactivates the tube 79a and the solenoid 77a. Armature 86a of this solenoid, in addition to breaking the holding circuit of tube 790:, rclights the lamp 264 concurrently with the de-energization of clutch 1661; at armature 7812 so that the disk 2%, rotating with sprockets 164a and limb, begins to generate counting pulses at the very instant when machine i) resumes its motion in step with machine 16th:. It will be apparent that, if edge E had been scanned prior to edge E, the release of solenoid 77a with continued energization of solenoid 7712 would have temporarily arrested the s rocket 164a so that machine a would have been kept waiting at the fabric edge while machine 10% moved toward it.

As the two machines advance in unison, photocell 265 receives the counting pulses from generator disk 203 and lamp 264 so as to step the decadic tubes 3t 31 and 32 in the manner describedv in my above-identified prior patent. The beam positions of these tubes, which can be monitored visually with the aid of the numerical indicia provided on one of the sides of counter Z66, initially correspond to the complemental value stored on the preselector 267, i.e., 946, so that after 54 counting pulses the counter 266 is triggered to close its contacts 58. This operation produces the following results:

(A) Drive motor 201 is de-energized and braked to standstill as the magnet 72 operates momentarily to advance the wiper arm '71 onto an unconnected contact so that solenoid 70 releases and breaks the motor circuit at its armatures 68 and 63';

(B) An impulse is transmitted via contact springs 82', 82 of unoperated starting switch 31 to relay 115 which attracts its armature 15' to actuate the starting solenoids 96a and 96b of machines 166a and 100b, thereby initiating the usual fabric-clamping and sewing operations thereof;

(C) Restoring magnets 9t), 91 and 92 are reoperated to reset the preselector 207 to zero; and

(D) Magnet 56 again operates in parallel with the restoring magnets of the pres'elector to restart the motor 34 of the program unit 263.

While needle 76b sews on the first button B and needle 76a stitches the first buttonhole H the needles returning thereafter to their respective starting positions on lines Ob and a, disk 36 rotates as before to preset the selector 207 in accordance with the numerical value stored in its sector S peg 42 acting upon switch 49, then arrests the disk in position P in the manner previously described. Thus, the complemental value 915 is next stored in preselector 297 and impressed upon the counting tubes 30, 31 and 32. Shortly thereafter, completion of the first stitching operation by machine 1619a releases the clamping lever 63 and causes the reoperation of stepping magnet 73 which had been temporarily released at contact 64 upon the actuation of that lever. Thus, wiper arm 71 takes another step and recloses the circuit of solenoid 76 to start the motor 261. The positioning of the machines 160a and ltltib for the sewing of subsequent buttons and buttonholes proceeds in analogous manner.

In the last phase of the operating cycle of program unit2tl8, i.e., with disk 36 rotating from position P to position P peg 42 actuates the switch 66 just before peg 452 operates switch 49 to arrest the disk in the manner described. Closure of switch 66 energizes the solenoid 61 which now trips the tilting relay 16 into its alternate position. Relay 16 operates with a delay sufiicient to allow completion of the sewing operations then in progress which involve the penultimate (i.e., fourth) button and buttonhole. The contactor vessel 65, tilting with relay vessel 62, is so designed that its mercury pool will not touch the contacts 65 upon its'counterclockwise swing (as viewed in FIG. 1), The mercury pool in vessel 62, however, now open-circuits the contacts 62", thereby insulating the magnet 56 from counter contacts 58, and bridges the contacts 62 to place a shunt across clampinglever contacts 64 whereby magnet '73 remains energized throughout the final buttonhole-stitching operation and wiper arm 71 will not be stepped. The delayed return I swing of tilting relay i6, occurring after this final stitching operation, restores the electromagnetic switch 269 to the control of counter 266 and, in vessel 65, momentarily short-circuits the contacts 65' to pulse the return solenoid 66 so that link 116 is shifted toward the right, being latched in its shifted position by the engagement of its shoe 166' with detents 67a and 67b. The latching movement of these detents also opens a pair of circuit breakers 114a and 1141) connected in parallel between one of the terminals of armature 68", on one hand, and,

on the other hand, magnetic clutches 166a and 16611, respectively. Motor 201, energized in its reverse direction via armatures 68 and 68, rotates continuously as the armature 63 so that sprocket 164i) is decoupled from shaft 21 and machine ltltibcomes to a halt. Again, if machine 160a had been the first to return to its starting position, it would have been immobilized by the energization of magnetic clutch 164a via armature 63 and closed circuit breaker 114a.

When both machines have completed the homing run, shoe 116 is unlatched so that link 116 returns to neutral and motor 261 is de-energized. With armature 68 spaced .frorn' its terminals, the reclosure of circuit breakers 114a and 114i; is without eifect upon the magnetic clutches 166a and 3166b. The system has now resumed a position in which a new cycle can be initiated by momentary actuation of the starting switch 81.

In order to deactivate the system, on-oif switch 17 is rotated clockwise into its oil position in which its arm bridges a pair of unconnected terminals 127, 128. Just before reaching this position, the switch arm briefly con tacts a terminal fig whereby one further pulse is transmitted to stepping magnet 73. This advances the wiper arm 71 onto one of its live bank contacts but is without further effect since bus bar 121 is disconnected from source 123 at this time. Such stepping of wiper arm 71 .is necessary, however, because the switch 17 will energize the terminal 126 just before reaching its on position whereby a further pulse will be applied to magnet '73 to step the arm 71 onto one of'its dead contacts; this is the position in which it must be just before operations are resumed by actuation of the starting switch $11.

It will be apparent that the system herein disclosed will be somewhat simplified if only a single machine is to be controlled thereby. With machine with removed, for example, electronic relay 14b can be omitted along with solenoid armatures 78a and 68", detent 67b as well adapted to trigger a switching process upon attainment of a present count and provided with means forrestoring it to a zero position. These and other modifications,

which are believed to be readily apparent to persons skilled in the art, are intended to be embraced within the spirit and scope of the invention as defined in the appended claims.

Iclaim:

1. A system for the control of aplurality of machines each having tool means adapted to perform an operation at a predetermined location on a workpiece of sheet material, comprising a support for said workpiece, drive means for jointly displacing said machines relatively to said support,distance-measuring means coupled with said drive means for arresting the latter at said locations preparatorily to performance of said operation by said tool means, individual edge-detecting means on each of said machines trained upon the path of said workpiece, and control means individually responsive to operation of any of said edge-detecting means upon the passage a of a proximal edge of saidworkpiece through a predetermined position relative to the associated tool means .for decoupling the respective machine from said drive means, said control means being jointly responsive to all said edge-detecting means for recoupling each decoupled machine to said drive means and advancing all said machines in unison upon operation of the last of said edgedetecting means, said distance-measuring means being actuatable by said control means upon resumption of the advance of all said machines.

2. A system according to claim 1 wherein said edgedetecting means of at least one of said machines is adjustable relatively to the associated tool means in the direction of advance.

3. A system according to claim 1 wherein said drive.

means includes a common shaft and magnetic clutches individually coupling said machines to said shaft, said clutches being selectively releasable by said control means.

4. A system for the control of a plurality of machines each having tool means adapted to perform a series of operations at predetermined spaced-apart locations on a workpiece of sheet material, comprising a support for said workpiece, drive means for jointly displacing said machines relatively to said support, distance-measuring means coupled with said drive means for arresting the latter at the first of said locations and subsequently at other of said locations preparatorily to performance of 1 said operations by said tool means, individual edgedetecting means on each of said machines trained upon the path of said workpiece, and control means individually responsive to operation of any of said edge-detecting means upon the passage of a proximal edge of said workpiece through a predetermined position relative to the associated tool means for decoupling the respective machine from said drive means, said control means being jointly responsive to all said edge-detecting means for recoupling each decoupled machine to said drive means and advancing all said machines in unison upon operation of the last of said edge-detecting means, said distance-measuring means being actuatable by said control means upon resumption of the advance of all said machines.

5. A system according to claim 4, further comprising joint tool-controlling means for said machines and reversing means for said drive means controllable by said tool-controlling means upon completion of the last operation on said workpiece for restoring said machines to their initial positions relative to said support, said reversing means including circuit means responsive to the arrival of any of said machines in said initial position for decoupling it from said drive means.

6. A system according to claim 5 wherein said drive means includes a common shaft and magnetic clutches individually coupling said machines to said shaft, said clutches being selectively releasable by said control means and said reversing means.

References Cited by the Examiner UNITED STATES PATENTS 2,483,138 9/49 Helmer 112-219 2,970,557 2/61 Schwab et al 112-67 X 3,025,444 3/62 Myska 112-67 X 3,072,081 1/63 Milligan et al. 112-2 3,074,632 1/63 Braun et al. 112-2 JORDAN FRANKLIN, Primary Examiner. DAVID J. WILLIAMOWSKY, Examiner. 

1. A SYSTEM FOR THE CONTROL OF A PLURALITY OF MACHINES EACH HAVING TOOL MEANS ADAPTED TO PERFORM AN OPERATION AT A PREDETERMINED LOCATION ON A WORKPIECE OF SHEET MATERIAL, COMPRISING A SUPPORT FOR SAID WORKPIECE OF SHEET MEANS FOR JOINTLY DISPLACING SAID MACHINES RELATIVELY TO SAID SUPPORT, DISTANCE-MEASURING MEANS COUPLED WITH SAID DRIVE MEANS FOR ARRESTING THE LATTER AT SAID LOCATIONS PREPARATORILY TO PERFORMANCE OF SAID OPERATION BY SAID TOOL MEANS, INDIVIDUAL EDGE-DETECTING MEANS ON EACH OF SAID MACHINES TRAINED UPON THE PATH OF SAID WORKPIECE, AND CONTROL MEANS INDIVIDUALLY RESPONSIVE TO OPERATION OF ANY OF SAID EDGE-DETECTING MEANS UPON THE PASSAGE OF A PROXIMAL EDGE OF SAID WORKPIECE THROUGH A PREDETERMINED POSITION RELATIVE TO THE ASSOCIATED TOOL MEANS FOR DECOUPLING THE RESPECTIVE MACHINE FROM SAID DRIVE MEANS, SAID CONTROL MEANS BEING JOINTLY RESPONSIVE TO ALL SAID EDGE-DETECTING MEANS FOR RECOUPLING EACH DECOUPLED MACHINE TO SAID DRIVE MEANS AND ADVANCING ALL SAID MACHINES IN UNISON UPON OPERATION OF THE LAST OF SAID EDGEDETECTING MEANS, SAID DISTANCE-MEASURING MEANS BEING ACTUATABLE BY SAID CONTROL MEANS UPON RESUMPTION OF THE ADVANCE OF ALL SAID MACHINES. 